A known door lock system is disclosed in Japanese Patent Laid-Open Publication No. Hei 6(1994)-288131, published without examination. This door lock system includes a locking-and-unlocking mechanism and a closing mechanism which are driven by respective electric motors.
Another known door lock system is disclosed in Japanese Patent Laid-Open Publication No. Hei 7 (1995)-217288, published without examination. This door lock system includes a locking-and-unlocking mechanism and a double lock mechanism which are driven by respective electric motors.
If one were to develop, based on a combination of the systems described in the two documents mentioned above, a door lock system having a closing mechanism, a locking-and unlocking mechanism, and a double lock mechanism, the system would require a total of three electric motors. However, such a system would be rather heavy, excessively large in size, and expensive to manufacture.
In light of the foregoing, a need exists for a door lock system possessing features similar to those described above, but which is smaller, less expensive, and lighter than would otherwise be required.